Difference between Floating and Self Ip's

Possibly. If you are using SNAT automap on the LTM, then you will need to configure the floating IP address in your admission rule because all traffic will originate from it. If you configure an explicit SNAT IP or pool, those will require admission also. If you are not using SNAT, then you should only require the Self IP's to allow for monitoring, but would also need to permit all client traffic from the internet as well, since the F5 will not change the source IP of the packet without SNAT enabled.